1. Field of the Invention
The present invention relates to activating or authorizing remote controls for gaining entry to a secure location, activating functionality, or the like.
2. Background Art
Remote controls provide convenience to users. However, if a remote control falls into the wrong hands, access to a secure location or activation of certain functionality may be obtained by an unauthorized user.
An example of such a remote control is a passive entry keyfob for automotive vehicles. This device allows entry into a vehicle when brought into close proximity. Additional functionality may include active functions such as lock/unlock doors, raise/lower windows, start engine, and the like.
Typical passive entry systems utilize multiple antennas on the vehicle to detect whether the keyfob is outside or inside the vehicle. If the passive entry keyfob is left inside the vehicle when the vehicle is locked, the passive entry system deactivates the keyfob. This prevents the system from incorrectly detecting the keyfob as being outside the vehicle, which can happen, for example, from signal leakage. Such an incorrect detection can result in various unwanted actions such as unlocking the door if the door handle is pulled (and no authorized keyfob is near the outside of the car), allowing a child left in the vehicle to start the vehicle using the push button start function, or the like. Typically, the keyfob is reactivated if another keyfob is used in a particular manner or if a vehicle door is unlocked using a key or a different authorized keyfob.
Present techniques for reactivating the keyfob may create security issues. For example, if a thief breaks into the vehicle and finds the keyfob, the thief can gain use of the keyfob by simply using the RKE function. Thus, if the vehicle has push button start functionality, the thief can drive away with the vehicle. This security issue can be addressed by fully deactivating both the passive entry functionality and the RKE functions of the keyfob. However, this creates an additional problem if the vehicle owner needs to reactivate the keyfob and this is the only keyfob available.